Measurement of parameters in liquids using optical sensors is commonplace. Reliable measurement of such parameters generally requires light to pass into the liquid, which generally requires light to first pass through a reasonably transparent medium, e.g., a light transference medium. Reliability issues can arise in the event of obstruction of optical transference through the medium, which may be caused by particulate matter.
Generally, boiler liquids are deaerated liquids that have unique features. Some unique features of boiler liquids include having very low levels of dissolved oxygen (e.g., less than about 10 ppb dissolved oxygen in conventional boiler feedwater) and having a pH of from about 9 to about 11. Particularly in boiler systems utilizing a form of treatment control based on light detection and/or measurement (e.g., fluorometry), some amount of corrosion will occur over time and deposit in the form of particulate matter onto a light transference medium, thereby causing some amount of optical obstruction of the light transference medium. Regarding detection and measurement methods that utilize light transference, the unique conditions of deaerated liquids, particularly boiler liquid, present a challenge to the user when a light transference medium becomes optically obstructed. Ideally, optical obstruction can be altogether prevented, and if optical obstruction occurs, it can be removed without disrupting detection, measurement, and/or treatment control via the light transference.